FRESHWATER AQUARIUM CARE | Basics & Fish Information | Maintenance
Principles for the Proper Set Up, Maintenance, Care and Feeding for Fresh-water Aquariums/ Tanks
Start with as large an aquarium as you can afford (even for bettas).
Obviously longer fish need more tank width and length. I would decrease the amount of fish proportional to the gallons in a tall aquarium or hexagon aquarium.
* To figure your tank size in gallons get your tank length, height, and width in inches then apply this formula (multiple all INSIDE dimensions up to where you expect the water level to be):
Consider substrate & large decor too by placing these in a 5 gallon bucket and using a measuring device such as a 2 quart pitcher figure displacement. For instance if a 5 gallon bucket filled with substrate and rocks will only accept 2 gallons of water, then take 3 gallons from the total tank/aquarium volume.To convert gallons to liters multiply by 3.785
(Ex. a 20 gallon tank = 75 liters).
What is much more important in determining how many fish you should add to your aquarium are these factors:
Find a good Aquarium or Pet Store. Look at their fish and see how well they are taken care.
Finally as to tank size; this is often a controversial subject among aquarist, especially well intentioned advanced aquarists. The bigger an aquarium you can afford, maintain and have space for, the better for many good reasons, BUT I have kept MANY aquariums under a variety of conditions and monitored them in controlled experiments and often a small aquarium can work for what many might consider over crowded conditions, provided excellent filtration, cleaning maintenance, circulation, feeding procedures (and quality food), chemistry, etc.
Here is an Aquarium Answers Post Dealing with this subject in a more factual way:
For the average aquarium I recommend 2-3” of #3 or pea sized gravel. This allows for less build up of hydrogen sulfide producing anaerobic bacteria. The down side to larger gravel is that it will allow for more waste particle or eaten food to accumulate. With proper maintenance though, waste accumulation should not be a major problem.
Sand is good for heavily planted aquariums, as it provides a better anchor for the roots and even more important sand traps nutrients and symbiotic bacteria needed by plant roots.
If your aquarium is going to be only lightly or moderately planted, I recommend sand only in the area around the plant roots and #3 size gravel elsewhere (otherwise you may develop Hydrogen Sulfide producing anaerobic bacteria).
Consider mixing different types of natural or colored gravels to achieve a look you like.
For hospital, breeding, or heavily populated temporary holding tanks; no sand or gravel is best. This allows for less waste build up, less possibility of waste matter or substrate absorbing medication in a hospital tank, and less rotting organic sludge in a holding tank.
For a little more info about substrate, please read this article:
Combined Suggested Aquarium Turnover Rates (per hours):
The size of your filters are also determined by other filters present in your aquarium as well as your aquarium "bio load" (number and size of fish and other inhabitants kept in an aquarium).
A Sponge Filter is an excellent compliment to most filters as the sponge filter can extend the tank size capacity of most filters they are used in conjunction with.
This article is a MUST READ:
Taking the aerobic bio filtration a step further, a Fluidized Sand Bed Filter can actually outperform most any high priced canister filter such as the Fluval FX5 and a Fluidized Sand Bed Filter and/or Premium Sponge Filter make a much less complicated alternative to messy canister filters (especially for those who find canister filters simply a pain to mess with).
For a small aquarium, a combination of a "Hang On the Back" (HOB) power filter (such as the SunSun Economy HOB Filter) and a Sponge Filter.
The SunSun 702 series is more than an economy filter in that it is similar to more pricey HOB filters (such as the Tetra EX) with its motor design that pulls water in rather than one that pushes water out which makes priming easier and also does not have the tendency to get carbon or other particulates stuck in the impeller.
For a mid size (or really any size) aquarium, you might consider a premium HOB Filter such as the AAP Tidal or Rena SuperClean Filter as well as the before mentioned Sponge filter for added redundancy.
For larger aquariums, a combination of a Fluidized and/or Canister Filter and an Internal Filter for cross circulation.
For Filter (& water pump) circulation, I recommend a minimum of a combined flow rate that turns over an aquarium a minimum of 5-6 times per hour, however 8-10 times would be better (although part of this can be simple circulation pumps), especially for fish such as goldfish.
There are Four Types of Filtration,
Care of these Filter Types:
*Biological; the removal of nitrogenous waste (ammonia, etc.), which is the most important type.Care: Rinse with de-chlorinated water (or used aquarium water) every two to six weeks depending upon flow through media. Change only when media can no longer be rinsed reasonably clean.
A common mistake with basic aquarium set ups this simple single cartridge only filters (especially the simple single cartridge filter kits sold at Walmart, PetsMart, etc.), is to throw way the cartridge during routine maintenance. Unfortunately if this is the sole filter, every time the filter cartridge is thrown out, the majority of the essential Aerobic Autotrophic nitrifying bacteria is thrown away too.
*Mechanical; the removal of larger debris (organic and inorganic) before it can go through the nitrogen cycle (organic) by means of filter fiber, sponges or other similar media.
Care: Change or rinse every two to six weeks depending upon condition of filter media (how fast it "clogs, etc.)
*Chemical; The removal of chemical contamination via carbon, zeolite or many other products. This becomes less important in a healthy, established aquarium. Carbon is often overused in healthy well established aquariums. If I even use carbon, I will generally use only one teaspoon per 5-10 gallons. I do add more and change it more often in tanks treated with medication or a new aquarium.
Care: Change the carbon every 4-6 weeks depending upon water parameters carbon is being used to improve. Carbon may need to be changed or "refreshed" after each treatment with medications (not water conditioners)
*Germicidal; The use of UVC or ozone to kill disease pathogens and control the Redox potential (though ozone generators do NOT improve Redox Balance).
If an air pump is used for added circulation or to power a filter such as a Sponge Filter, placement of this pump can make quite a difference in its longevity.
If not possible adding a check valve is a must, as well looping the tubing about three times at the top of the tank can help.
Additional control of air flow can be done with airline control valves and Ts. Use of both T and valves can allow for bleeding off of air to prevent damage to the air pump by just using a valve to lower air volume.
For Suggested Freshwater Aquarium Filter set ups (depending upon the aquarium size, please see this article):
HEATERS & WARM WEATHER COOLING:
Most tropical fish do well at a temperature between 76 and 80 degrees Fahrenheit. (Discus prefer warmer).
Also remember that bettas are still basically tropical fish too, so if they are kept in a bowl try and keep them in a warm area of your house, preferably above 70 F.
If your temperature fluctuates between night and day, even though you have the correct wattage heater, you may have an “Automatic” heater vs. a “Thermostatic” heater.
For more about aquarium heaters, please see this more in depth article:
Cooling; Sometimes cooling a tank in the warm summer months can be an issue, and most freshwater aquarists cannot afford an expensive chiller (which can cost $500 +). In many applications, even a an air conditioner is not a viable option.
A few suggestions include floating frozen 2 liter plastic pop bottles in the aquarium and/or the use of a wet towel draped over the tank with a fan aimed at this towel along with an open lid if viable depending upon fish kept (not viable for Arowanas for instance since they will jump out), this works similar to human perspiration or an evaporative cooler (do not cover lights or anything that would still trap the heat trying to escape via evaporation).
I often had clients leave a wet towel & fan on their tank before leaving for work, then add a frozen bottle when they come home.
Other options can simply be to add a small room air conditioner and set it at a high setting of 78 F. This can often be cheaper than both the purchase and operating cost of an aquarium chiller in my experience.
If tap water is used it will have to be treated to remove chlorine or even chloramines and heavy metals.
SeaChem Prime or Amquel Plus are excellent first choice products to use when ammonia and nitrite levels are an issue, as these do not interfere with the cycling process as other products can when used properly.
If ammonia/nitrites are not an issue, and especially with new fish or fish recovering from disease, AAP Res-Q is a must use water conditioner. This is the product I always had on hand in my professional aquarium maintenance route. AAP Res-Q is far superior to all similar slime coat products such as Stress Coat as the product produces a much better adhering slime and also has medications embedded to act as a medicated bandage.
RO (Reverse Osmosis) water can be used IF minor elements and electrolytes are added. NEVER use straight RO water or even worse, distilled water.
Salt is also commonly added to freshwater aquariums as a disease preventative, slime coat stimulant, or simply due to possible requirements by certain freshwater fish such as Livebearers or African Cichlids to have salt present the water.
For more about the use of salt in freshwater aquariums, as the use there of often is recommended as a cure all for everything or totally panned, neither of which view is correct based on the science behind correct use:
Generally 1 tablespoon per 5 gallons (35 liters) of water for a community tank is what works best.
It should also be noted that some catfish (such as Cory Cats) are very sensitive to salt and care should be given in use of salt when these fish are present.
Here is one source for an advanced salt that includes other essential elements:
AQUARIUM WATER TOP OFF FOR EVAPORATION (including ATO):
Evaporation of aquarium water is a constant issue for any aquarium, but much more so open top aquariums and/or aquariums with sumps.
Reference why not to use home/office water softener in aquarium:
Products such as SeaChem Replenish or AAP Regular Wonder Shells are recommended in the reservoir water used for toping off. For an AAP Wonder Shell, just 1/4 dose per water volume is all that is needed and even then, my experience has shown these dissolve very slowly when an ATO system is utilized.
Your aquarium will not be at peak biological filtration for 6 weeks (or more).
A better cycling product would be SeaChem Stability which is a blend of synergistic blend of aerobic (including encapsulated oxygen) and facultative bacteria.
I prefer to add gravel and/or used filter sponge or cartridge from another well established aquarium.
If you add plants (many such as hornwort remove nitrogenous waste directly), you can stock somewhat faster as the plants will remove ammonia too, but also usurp the establishment of nitrifying bacterial colonies.
Another method is fishless cycling include adding fish food to bring your ammonia to about 4-5 ppm or the use of un-scented ammonia where it is added into the aquarium (3-5 drops per gallon pure ammonia) so as to bring your ammonia level to 4-5 ppm. It then takes about 2-6 weeks for the aquarium to cycle.
Cycling is what is referred to as the Nitrogen cycle.
Aquarium cycling is a VERY important topic (more so for a beginner) and I highly recommend reading the FULL article below about The Aquarium Nitrogen Cycle.
This article will go into MUCH greater depth about all aspects of cycling and explain the truths and myths as well:
CHEMISTRY (& TEST KITS):
First, please note that this section is a VERY brief and basic outline of freshwater aquarium chemistry; for any aquarium keeper looking to go beyond just very basic aquarium keeping, please read these articles:
*The above noted Nitrogen Cycle Article
Next, it is generally helpful to know your new water source parameters (tap water, etc. used for filling your aquarium). This will help you make what is generally only minor adjustments to your chemistry with buffers and mineral supplements.
Summary of "Numbers" to Maintain:
Please see this article for more about lowering ammonia/nitrite and preventing high aquarium ammonia/nitrite:
*Nitrates; under 40-50 ppm (lower yet is always better)
Reference this article for information about controlling Nitrates:
Product Resource: Nitrate Test Kit from AAP
*GH: this is best above 100 ppm for 90% of FW fish and above 200 for over 60%
GH is also the parameter ESSENTIAL positive mineral ions (Cat-ions) are found in, and fish kept in water with inadequate mineral cations can suffer health problems over the long term.
Product Resource: Wonder Shells; Unique Version ONLY from American Aquarium
*pH; Stable is most important, but for general community tanks a 6.8-7.8 falls within most fish tolerances as long as there is pH stability since the pH scale is logarithmic and sudden changes can be deadly.
As well, pH depends very much on the fish you are keeping.
Please see this article for more on the subject of pH:
Product Resource for pH Test Kits: Aquarium Test Kits from AAP
*KH; VERY important for pH stability which is why I this is a more important test than pH in my experience and knowledge of aquarium chemistry.
Sea Chem Buffers and to some degree Aragonite can help maintain a high KH & pH when you desire an aquarium with a higher pH/KH especially where tap or well water is very acidic.
For a lower pH in aquariums where the tap water used is very high (usually 7.8 or above), I have used blends of RO (Reverse Osmosis) water and tap water.
Another method for lowering pH is crushed almond husk or Pillow Moss.
Note that GH does not directly affect pH.
Also note that calcium is also important for fish metabolism and fish health and healing (along with other essential electrolytes/minerals found in "GH").
With the above method of using RO (or DI) water in a blend with tap water and peat, I have still been able to maintain a a low but still healthy KH and GH level.
*Caution; Soft Water Use: water that originates from a home or office water softener that uses sodium (salt) should Never be used in any aquarium.
Suggested Test Kits;
*Test Strips, although generally not as accurate are still very useful for quick readings that are STILL ACCURATE ENOUGH (provided stored dry) for a beginner or intermediate aquarist to get a very good barometer of aquatic health.
For a more in depth article and explanation about Aquarium Test Kits, please follow this link:
Video about aquarium test kits:
For the average freshwater aquarium, lighting is not as important a consideration as it is for a planted freshwater aquarium or reef aquarium.
These same 6400 K high output CFL aquarium lights can also be purchased separately and used in standard incandescent aquarium (or other) light fixtures as pictured to the left.
A popular newer technology is the LED Aquarium light fixture.
For the highest output of useful light energy, the AAP AquaGro Colour Plus (excellent to bring out colors) and even more so the GroBeam LED Aquarium light are by far the leaders among all lights (including MOST ALL other LEDs) except maybe Metal Halides, but this may be cost prohibitive to many basic freshwater aquarium keepers.
Finally, good ole fashioned T8 & T12 aquarium lights such as the Aquarilux by Penn Plax that are available in lengths from 12 to 48 inches are still practical for a basic FW aquarium application.
I would NOT recommend standard incandescent light bulbs (which are unfortunately still sold in many aquarium supply outlets) and STRONGLY recommend the use of the self ballasted CFL aquarium lights that will fit into these incandescent fixtures.
Product Resource: Self Ballasted CFL Lights; 6400K.
Cool White lights also are NOT appropriate for aquariums due to poor lumens per watt, incorrect PAR and Kelvin output which can result in growth of Cyanobacteria or Brown Diatom Algae.
Please reference this article for more about Aquarium lighting from basics to advanced (also see the basic freshwater section in the summary near the end):
The benefits of live plants are they are great at nitrate removal and keep a natural balance to the aquarium, removing CO2 and adding oxygen (only during daylight).
For healthy plants I suggest a substrate of #00 sand mixed with products such as SeaChem Flourite or Eco Complete about 3-5 cm deep with a layer of #3 gravel on top about 2 cm deep.
You can substitute Flourite with a sandy top soil (although usually not as good a source of iron), by preparing the soil thus; Gather sandy top soil, add water with a 10/1 bleach solution, mix for a couple of minutes, then rinse (with a de-chlorinator for first rinse) until the water runs relatively clear.
It is important to note that dying plants can add to your ammonia, nitrite, nitrate and even kH problems (production of nitric acid through decay), so is important to keep your plants healthy.
For healthy plants you will need;
3-4 watts per gallon is quite outdated now, especially with the high end LED Aquarium Lights now available, as there is a lot more that goes into the equation than this (I am not referring to the many low end LEDs that have flooded the market via Amazon, etc, so do not make the mistake of comparing apples to oranges).
*SUBSTRATE for a healthy root structure;
*BIO AVAILABLE CARBON and a Proper gas exchange:
*PROPER NUTRIENTS OR ‘FERTS’:
Some Plants to Have:
FOR MY FULL PLANTED AQUARIUM ARTICLE, please follow this link:
Once you have removed your chlorine (if necessary) adjusted your temperature, checked basic water parameters (kH, pH, Ammonia), you can start with a few fish.
I recommend feeding high quality fish and plant based foods. Quality ingredients include: spirulina,
Whole Menhaden Fish Meal, FD Brine Shrimp, shrimp meal, Vitamin C & E, lobster shell.
Some quality foods include: Spirulina 20, Ocean Nutrition, Hikari, Aqua Master, and most notably AAP Custom by Fish Food Guru Clay Neighbors.
Product Resource: Clay Neighbor's AAP Custom Fish Food
For beginners feed your fish two to three times per day what they will consume in three minutes. This is a very basic rule and more applies to small fish and goldfish.
Feeding foods high in poor quality proteins can increase your nitrate levels, as an essential ingredient in protein is nitrogen, and if unusable by the fish, it is excreted, entering into the nitrogen cycle.
Just as importantly as to how much is how, I recommend with pellets in particular, but even with flakes to soak your food in water for 5 minutes prior to feeding. This softens the pellet, but more importantly prevents air from being released in the digestive tract and causing gas and infections.
For more information about correct feeding:
You should try and have a schedule of changing 20% (or more) of your water every week.
For our expanded article on aquarium cleaning, please see this article:
Generally there are three basic “Smell Problems”.
Green water is free floating algae.
The main causes are:
Since a UV Sterilizer is almost 100% effective in the eradication of green (pea soup) water, if you can afford this option, I would use one.
See this article comparing higher cost low pressure UV Bulbs and lower cost medium pressure UV Bulbs:
Actual UV-C Emission from a UV Bulb
For more about proper feeding, please read this article:
Quality Fish Food; What ingredients are needed for proper fish nutrition, growth and health.
Consider products such as Algone which is an excellent bio aid to nitrate control and thus many causes of green water.
As well SeaChem Purigen is another effective method for nitrate control and thus water clarity (it is a good compliment to Algone).
Also Phos-Zorb may help if phosphates are a cause/problem.
Sometimes it is simply a mater of improving your bio filtration by improving the quality of bio filter media.
Instead of the Bio Rings, balls, pads, and sponges that come with many filters, considering adding and/or replacing some of this with AAP Matrix or Aquarium Volcanic Rock. Both of these are very porous and can perform aerobic bio filtration at a much higher capacity than other more commonly used filter medium. As well these products can do something most standard bio filter media cannot do and that is perform bio de-nitrification which removes nitrates.
The end results is less "food" for green algae.
Aquarium Nitrate Control
Improve lighting to 6400 K lights or maybe higher kelvin temperature. If low quality lights are an issue, utilize better lights such as the T2 Aquarium Lights, Premium LED Lights, or the Compact Fluorescent Aquarium Lights.
Please note that even good aquatic lights loose much of their lumen output outside of the visible light spectrum within 6-12 months (except for Premium LEDs such as the TMC line), & even more so after a year.
So if your aquarium light is not the best light spectrum (6000-8000K) or is more than a year old changing it is a good idea.
Product Resource: Uncut Poly Filter Pads
See this article for more about poly filter pads and other filter media:
Aquatic Filter Media
Maintenance of Positive mineral ions (Electrolytes) such as magnesium and calcium.
Maintain a GH of at least 100 ppm and KH at least 50 (depending on fish kept). Wonder Shells are useful for this, so is aragonite in the filter.
After getting green water problems under control, the AAP Green Water Disks are helpful in keeping green, brown & grey water under control.
For more about algae control in Freshwater aquariums, please see the algae control section in the Planted Aquarium Article:
For Blue Green Algae problems [Cyanobacteria], please see this article:
A white or grey cloud is a bacterial bloom (Heterotrophs).
The main causes are:
The use of Potassium Permanganate found in products such as Jungle Clear Water may quickly solve this problem, however this often may be a temporary fix if other problems exist.
Please also read this article about the use and cautions of Potassium Permanganate use:
Aquarium Medications 3; Potassium Permanganate
Product Resource: Potassium Permanganate, Jungle Water Clarifier
After getting grey/cloudy water problems under control, the AAP Green Water Control Disks are helpful in keeping green, brown & grey water under control.
Yellow water is generally a high amount of dissolved organics, often pH/KH lowering tannins.
Often with yellow water, your aquarium will test lower in KH and pH (50 ppm & -6.8 respectively), as well often nitrates are above 40 ppm. This again is a generalization though.
What is noteworthy is that yellow water is NOT necessarily an indicator of poor water quality or other issues.
For fish such as Livebearers or especially Goldfish that prefer higher mineral/pH water, yellow water can be an indicator of the need for a water change and/or better filtration, especially chemical filtration.
Lowering 'Yellow' in water:
SPECIFIC FRESHWATER FISH INFORMATION
Our recommended dealer to supply the best possible freshwater livestock to your local fish store:
This is only very general information, please follow the resource links or visit the much more in depth articles about each of these subjects and more available at these sites:
If you have found this site helpful (or the sister site Aquarium and Pond Answers), please consider a donation to help with the 100s of hours of research and regular updates that go into these articles:
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